Unconditionally set last_work_seen while in the SYNCER_RUNNING state so that last_work_seen has a reasonable value at the transition to the SYNCER_SHUTTING_DOWN state, even if net_worklist_len happened to be zero at the time.
Unconditionally set last_work_seen while in the SYNCER_RUNNING state
so that last_work_seen has a reasonable value at the transition
to the SYNCER_SHUTTING_DOWN state, even if net_worklist_len happened
to be zero at the time.

Initialize last_work_seen to zero as a safety measure in case the
syncer never ran in the SYNCER_RUNNING state.

Tested by:	phk

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase